Calibration method and apparatus for potentiostats

Abstract

A system and method for potentiostat calibration includes a conductive substrate, a model film placed on the substrate, an electrolyte, and a potentionstat for obtaining calibration data from tests conducted on the model film. The electrolyte is disposed at a first side of the model film opposite the substrate, and in electrical contact with the model film. The potentiostat includes a working electrode, a reference electrode, and a counter electrode. The working electrode is electrically connected to the substrate, and the reference and counter electrodes are positioned at the electrolyte.

1 . A system comprising: 
 a conductive substrate;    a model film placed on the substrate;    an electrolyte disposed at a first side of the model film opposite the substrate, and in electrical contact with the model film; and    a potentionstat for obtaining calibration data from tests conducted on the model film, the potentiostat having a working electrode, a reference electrode, and a counter electrode, wherein the working electrode is electrically connected to the substrate, and wherein the reference and counter electrodes are positioned at the electrolyte.    
   
   
       2 . The system of  claim 1 , wherein the model film comprises a polymer material.  
   
   
       3 . The system of  claim 1  and further comprising: 
 a conductive paste disposed between the model film and the substrate.    
   
   
       4 . The system of  claim 3 , wherein the conductive paste is arranged as a thin film.  
   
   
       5 . The system of  claim 1 , wherein the first side of the model film has a surface area of at least about 11.4 cm 2 .  
   
   
       6 . The system of  claim 1 , wherein the substrate is a stand-alone plate.  
   
   
       7 . The system of  claim 1 , wherein the substrate comprises a metallic material.  
   
   
       8 . The system of  claim 1 , wherein the substrate comprises at least a portion of a base plate of an Electrochemical Impedance Spectroscopy testing system.  
   
   
       9 . The system of  claim 1 , wherein the model film includes an adhesive disposed thereon.  
   
   
       10 . The system of  claim 1 , wherein the model film has an impedance range that is similar to coating samples desired to be tested using the potentiostat.  
   
   
       11 . The system of  claim 1 , wherein the model film has a substantially constant film thickness.  
   
   
       12 . The system of  claim 1 , wherein the model film has a reproducible EIS spectra.  
   
   
       13 . The system of  claim 1 , wherein the model film has known electrical properties.  
   
   
       14 . The system of  claim 1 , wherein the model film has a substantially homogeneous composition.  
   
   
       15 . The system of  claim 1 , wherein the model film is substantially defect-free.  
   
   
       16 . The system of  claim 1 , wherein the model film has substantially smooth outer surfaces.  
   
   
       17 . A method for calibrating a potentiostat, the method comprising: 
 engaging a model film with the potentiostat;    testing the model film with the potentiostat to obtain calibration test data relating to electrical properties of the model film; and    comparing the calibration test data to control data.    
   
   
       18 . The method of  claim 17  and further comprising: 
 placing the model film on a conductive substrate.    
   
   
       19 . The method of  claim 18  and further comprising: 
 placing a conductive paste between the model film and the substrate.    
   
   
       20 . A method of calibrating a potentiostat used for Electrochemical Impedance Spectroscopy testing of coating samples, the method comprising: 
 engaging a polymer model film with the potentiostat, wherein the model film has an impedance in an range that approximates an impedance for a sample desired to be tested with the potentiostat;    testing the model film with the potentiostat to obtain calibration test data relating to electrical properties of the model film;    comparing the calibration test data to control data; and    adjusting a recorded output of the potentiostat as a function of the comparison between the calibration test data and the control data.